The invention is directed to improvements in a vacuum pump rotor, at least one vane separating an inlet and an outlet, and switch-off means. A vacuum pump of this type is known (German Offenlegungsschrift No. 28 08 208). In this known design, each vane is fully removable from its track within the housing bore, so that all friction is avoided, as well as impact noises. However, this pump necessitates the use of a specialized actuation device, substantially comprising a work-performing cylinder, and it is not always possible to mount an actuation device of this kind on the pump, particularly when space is restricted.